The present invention relates generally to implantable medical devices, such as implantable cardiac pacemakers, implantable cardioverter/defibrillators (ICD""s), heart monitors, or any other medical device that stores therapy and diagnostic data for subsequent retrieval and display by an external instrument, device or programmer. More particularly, the invention relates to a software-based system, including a user interface, which orders diagnostic data in a time-line approach related to significant milestones such as events occurring, for example, at implant, during post-implant therapy and diagnostic follow-up sessions. The use of this system enables a physician to rapidly and accurately retrieve, evaluate and process relevant diagnostic and therapeutic data acquired and stored by the implantable device.
Many types of implantable medical devices have been developed since 1960, including single and dual chamber pacemakers, pacemaker-cardioverter-defibrillators (PCDs), and implantable cardioverter-defibrillators (ICDs). All of these devices deliver therapies based on automatic diagnostic evaluations of cardiac activity. Further, these devices store event, diagnostic and therapy data in addition to the control of other operations. Moreover, these devices are programmable to change both their functional and operational parameters to match patient diagnostic and therapy needs.
Accordingly, cardiac devices have become progressively more sophisticated and capable of performing complex operations in response to a variety of inputs. The processing and operating control systems of such cardiac stimulators and monitors typically include a memory for storing operating modes and parameter values as well as keeping track of delivered therapies and diagnostic events related to the treatment of cardiac disease.
Implantable devices generally store a wide variety of different types of diagnostic data that assist a physician in evaluating both a patient""s cardiac function and the operation of the implanted device. The specific collections or xe2x80x9crecordsxe2x80x9d of diagnostic data stored by the implanted device may be generally divided into three distinct categories: a) device-related, such as rate histograms to record paced and/or sensed rates over a complete rate range; b) patient-related such as atrial and/or ventricular tachyarrhythmia monitors; and c) therapy-related, such as mode switch, cardioversion, or defibrillation therapies. The number of these different records of diagnostic data in any one category can be quite highxe2x80x94often in the range of hundreds or more. Such information is useful not only in optimizing device programming but also in the management of the patient""s arrhythmias and other cardiac/physiological conditions.
Often, the implantable device stores intracardiac electrogram (xe2x80x9cIEGMxe2x80x9d) data preceding or following a detected arrhythmia along with the device""s response to that arrhythmia, such as a defibrillation or cardioversion pulse. Cardiac stimulators typically process patient electrograms (EGMs) and acquire or measure physiological data for diagnosis. Such data is usually stored, especially if they relate to intrinsic heart rate or arrhythmic episodes. Stored data may be subsequently uplinked by telemetric means and displayed by interrogating the device memory using an external programmer. Such telemetered data are then analyzed, and may be employed to establish or refine the operating modes and parameters of the device operating algorithms. For example, the implantable device may be re-programmed to operate in a new mode or a new parameter value may be downloaded into memory to improve therapy response time.
A wide variety of programming and interrogation techniques have been devised for implantable medical devices. An example of a current medical device programmer is the Model 9790 universal programmer for bradycardia pacemakers and tachyarrhythmia devices. This device is described in U.S. Pat. Nos. 5,372,607, 5,345,362, and 5,350,411. The foregoing patents are hereby incorporated herein by reference in their respective entireties.
The xe2x80x9cMedtronic Kappa(copyright) Pacemaker Programming Guidexe2x80x9d published by Medtronic(copyright), Inc. for the Kappa 700/600 Series Pacemakers, describes the operation of a typical modem pacemaker, and is incorporated herein in its entirety. The xe2x80x9cGem(copyright) II DR System Reference Guidexe2x80x9d also published by Medtronic, Inc. for the operation and programming of the 7273 Gem II DR dual chamber implantable cardioverter defibrillator describes the operation of a typical modern ICD.
The various records of diagnostic data may be retrieved from the implantable device for display and evaluation, for example, using a programmer, which uses telemetry to communicate with the implanted device and download diagnostic data. This operation typically occurs during routine follow-up visits of the patient to the clinic. To view a particular record of diagnostic information (e.g., a record of defibrillation interventions), the physician uses the programmer interface to designate the record to be retrieved, and then initiate the retrieval. The programmer, in turn, interrogates the implantable device to cause the implantable device to transmit the selected record, and then receives and displays the selected record, typically in a graphical format, on the screen.
The physician, to optimize performance of the system, may need to view diagnostic data before reprogramming operating modes and parameter values. At times, a physician may have difficulty determining which diagnostic data will yield optimum information for a given patient. Uncertainty in selecting the correct data is often heightened by the limited amount of time physicians have to spend with individual patients. Sometimes it is impossible for a physician, faced with the wealth of diagnostic data, to evaluate with any degree of confidence how well or appropriately a cardiac stimulator has operated in the programmed operating modes and parameter values.
For example, assuming that no adjustments are made to the implantable device parameters, it will typically take the physician 20 to 25 minutes to sequence through the steps of the follow-up protocol. This is due in-part to the need for the physician to interactively specify each diagnostic record to be retrieved, and then wait for the programmer to retrieve and display the data record. In addition to affecting the physician""s efficiency, this time penalty is often burdensome to the patient, since the patient typically must hold the telemetry wand in place throughout most or all of the procedure.
Another problem with the current practice is that the physician often fails to retrieve and evaluate clinically significant diagnostic data records stored within the implantable device. It is currently common practice for the physician to retrieve certain diagnostic data records only if the patient is or reports a symptomatic event. As a result, clinically significant data is frequently overlooked during the diagnostic decision process. One reason for this under-utilization of diagnostic information is the amount of time required, to retrieve and review each diagnostic record. Another reason is due to the storage of very large diagnostic data records in the implantable device memory. Because these records are not organized in a logical user-friendly manner, it is burdensome for the physician to view all of the available diagnostic records and determine their relevancy to the patient under consideration.
One approach to solving this problem is taught in U.S. Pat. No. 5, 833,623, System and method for facilitating rapid retrieval and evaluation of diagnostic data stored by an implantable medical device, issued to Mann, et al. and hereby incorporated by reference in its entirety. That invention addresses the issues via software incorporated into an implantable device programmer that has a variety of interrelated features for automating and permitting the customization of the follow-up evaluation process. This solution provides the opportunity for the physician to create a customized protocol that eases the burden on the physician to retrieve relevant diagnostic data. A similar approach is described in aforementioned xe2x80x9cMedtronic Kappa(copyright) Pacemaker Programming Guidexe2x80x9d wherein is described a xe2x80x9cChecklistxe2x80x9d approach to customize a protocol to ease the follow-up burden. In both cases, the ultimate goal is to ensure the compliance of the physician, clinician, or technician to a standardized protocol. Neither approach eases the burden of organizing the immense diagnostic data into a more usable format. While currently available graphical format adopted by all manufacturers eases the interpretation process, all the recorded device data into a time-based approach that simplifies the selection of the appropriate record(s) for the busy physician is not available.
An alternative solution, known to those skilled in the art, involves the implantation or co-implantation of a medical device that records the patient""s cardiac rhythm over a set of time periods, as described in U.S. Pat. 6,102,874, Implantable medical device for tracking patient functional status, issued to Stone, et al, and incorporated herein by reference in its totality. These devices, however, merely record the patient""s cardiac rhythm when triggered either by the patient or by a set of events. There is a limit to the number of episodes that can be collected and captured for later interrogation and display on a programmer. Moreover, such episodes will not be captured or displayed under any particular category. Thus, for example, it is left in the hands of a busy physician to interpret the stored ECG/EGM and determine if and when defibrillation therapy was delivered.
The present invention provides, inter alia, various structures and methods to overcome the limitations of the prior art.
The present invention facilitates the task of accessing a patient""s therapy history by organizing stored data into convenient categories related to the time the episodes and events were captured. These categories currently include, but are not limited to, the following organizational classifications: Checkup, Implant, Therapy, Medical, Magnet, and ICD Alert data/information. The categories are arranged in chronological order on a display screen of the programmer or an external device such that the oldest information (from Implant) appears under an icon on the extreme left side of the screen, with the most recent information on the right side of the screen. As the memory capacity of an implanted pacemaker or ICD devices increases, it is certain that these categories will be expanded. The present invention provides scalability for such expanded memory.
In one aspect of the present invention, upon selecting a xe2x80x9cTime Linexe2x80x9d display screen, the user initiates a programmer""s selection apparatus to choose a desired icon which action, in turn, reveals a corresponding detailed information stored under that category. For example, the physician may select the xe2x80x9cTherapyxe2x80x9d icon to get an idea of the frequency and episodes of defibrillation therapies and how these relate to the ICD Alerts. Accordingly, the physician might wish to toggle between the xe2x80x9cTherapyxe2x80x9d and xe2x80x9cICD Alertxe2x80x9d icons. The episodes, therapies, and alerts may be aligned to indicate the same time and date.
In yet another aspect of the invention, a physician may need to determine whether a change in medication has had a favorable impact on the number and/or frequency of the ventricular arrhythmia. The physician may only, for example, wish to determine whether the onset of an AV nodal tachycardia had preceded an ventricular arrhythmia. In this case, the physician would simply drill down into the data accumulated under the xe2x80x9cTherapyxe2x80x9d icon to access the relevant recorded data.
The foregoing features are some of the representative distinguishing elements of the present invention. These features will be more readily understood by referring to the following detailed description of preferred embodiments and figures.